1. Field of the Invention
The present invention relates to an installation for manufacturing products consisting of component elements, for example to an installation for manufacturing motor vehicles.
2. Description of the Prior Art
There has been proposed an installation of this type in which the component elements, secured on movable transport units by holding devices, are conveyed along a track forming a production line to storage zones in working stations and/or to associated buffer stations.
The previously proposed installation is provided with transport units, driven by electric motors, which are controllable as regards both direction of travel and speed of travel by a control conductor which extends along the track between and to the working and/or buffer stations if required. Because of this electronic control of the speed and direction of the transport units their running costs are very high, so that the proposed installation involves a high capital outlay and high maintenance costs, particularly since the necessity of buffering between the working stations requires the number of transport units to be considerably larger than the number of working stations. Also, the space required by this previously proposed installation as regards the buffer stations is uneconomically large, since in these stations the transport units can only be placed side by side in readiness to be called upon.